Share-based Compensation (Details 3) (SARs activity [Member], USD $) In Thousands, except Share data, unless otherwise specified	1 Months Ended		12 Months Ended
	May 14, 2010	Apr. 04, 2007	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011		Dec. 31, 2009	Dec. 31, 2008
SARs activity [Member]
Summary of SARs activity under the 2005 Plan
Stock Appreciation Rights (SARs), Outstanding, Beginning Balance (in shares)			597,392	805,910	711,353
Stock Appreciation Rights (SARs), Granted (in shares)	95,100	190,200	0	204,500	242,041		212,850	196,900
Stock Appreciation Rights (SARs), Cancelled/Forfeited (in shares)			(41,114)	(22,360)	(22,720)	[1]
Stock Appreciation Rights (SARs), Exercised (in shares)			(349,044)	(390,658)	(124,764)
Stock Appreciation Rights (SARs), Outstanding, Ending Balance (in shares)			207,234	597,392	805,910
SARs Weighted Average Exercise Price
Weighted Average Exercise Price, Outstanding, Beginning of the year (in dollars per share)				$ 16.35	$ 12.68
Weighted Average Exercise Price, Granted (in dollars per share)				$ 29.31	$ 24.45
Weighted Average Exercise Price, Outstanding, End of the year (in dollars per share)			$ 25.85		$ 16.35
Stock Appreciation Rights (SARs), Exercisable (in shares)			39,691
Weighted Average Exercise Price, Exercisable (in dollars per share)			$ 18.80
Weighted Average Remaining Contractual Life, Outstanding			56 months
Weighted Average Remaining Contractual Life, Exercisable			49 months
Weighted Average Grant Fair Value of SARs, Outstanding (in dollars per share)			$ 22.06
Weighted Average Fair Value of SARs, Exercisable (in dollars per share)			$ 27.04
Aggregate Intrinsic Value, Outstanding			$ 4,123
Aggregate Intrinsic Value. Exercisable			$ 1,070

[1] Of the SARs granted in 2008, 13,123 were canceled in 2011 due to the closing price of the Company’s common stock not achieving a specified price target for twenty trading days during any sixty day trading day period.